Effects of Preoperative Abnormality of Posterior Tibial Tendon on the Surgical Outcomes of Medial Osteochondral Lesion of the Talus.

BACKGROUND: Although surgical treatment for osteochondral lesion of the talus (OLT) can obtain good clinical outcomes, the rate of return to sports is variable. It is reported that medial OLT unrelated to trauma has abnormal structures in the medial aspect, which may induce the medial OLT due to the medial instability. The posterior tibial tendon (PTT) plays an important role in the stabilization of the foot, and high mechanical stress may be added to the PTT to compensate for medial instability in medial OLT. We investigated whether abnormal PTT findings on preoperative magnetic resonance imaging (MRI) in patients with OLT affect clinical outcomes after surgery.  Methods: Eighty-one ankles in 74 patients who were treated surgically for OLT were included in this study (41 men and 33 women; mean age, 26.0 years). Abnormalities of the PTT were evaluated using preoperative MRI. The Japanese Society for Surgery of the Foot (JSSF) scale, arch height, and ankle activity score (AAS) on standing plain radiogram were compared between patients with and those without preoperative PTT abnormalities. RESULTS: Twenty-five ankles (30.9%) had PTT abnormalities on preoperative MRI. All patients with preoperative PTT abnormalities were medial OLT. There were no significant differences in the preoperative JSSF scale in the procedures for OLT. The postoperative JSSF scale and arch height were significantly lower in patients with preoperative PTT abnormalities than those without them. AAS in patients with preoperative abnormalities significantly decreased at the final follow-up.  Conclusion: PTT abnormalities on preoperative MRI may affect clinical outcomes even in preoperative asymptomatic patients in the medial OLT unrelated to trauma.

The Relationship Between Calcaneofibular Ligament Injury and Ankle Osteoarthritis Progression: A Comprehensive Analysis of Stress Distribution and Osteophyte Formation in the Subtalar Joint.

BACKGROUND: Ankle osteoarthritis (OA) mainly arises from trauma, particularly lateral ligament injuries. Among lateral ligament injuries, ankles with calcaneofibular ligament (CFL) injuries exhibit increased instability and can be a risk factor ankle OA progression. However, the relationship between CFL injury and OA progression remains unclear. Therefore, this study aims to assess the relationship between CFL injuries and ankle OA by investigating stress changes and osteophyte formation in subtalar joint. METHODS: We retrospectively reviewed the magnetic resonance imaging (MRI) and plain radiographic evaluations of 100 ankles of 91 patients presenting with chronic ankle instability (CAI), ankle OA, or other ankle conditions. The association between CFL injuries on the oblique view of MRI and the severity of ankle OA (based on Takakura-Tanaka classification) was statistically evaluated. Additionally, 71 ankles were further subjected to CT evaluation to determine the association between the CFL injuries and the Hounsfield unit (HU) ratios of the subtalar joint and medial gutter, and the correlation between the subtalar HU ratios and osteophyte severity were statistically evaluated. RESULTS: CFL injury was observed in 35.9% (14/39) of patients with stage 0, 42.9% (9/21) with stage 1, 50.0% (10/20) with stage 2, 100% (9/9) with stage 3a, and 90.9% (10/11) with stage 3b. CFL-injured ankles exhibited higher HU ratios in the medial gutter and lower ratios in the medial posterior subtalar joint compared to uninjured ankles. A negative correlation was observed between medial osteophyte severity and the medial subtalar joint HU ratio. CONCLUSION: Our findings suggest that CFL injuries are common in severe ankle OA impairing the compensatory function of the subtalar joint through abnormal stress distribution and osteophyte formation. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Effect of a compression staple on correction of varus deformity during arthroscopic ankle arthrodesis.

BACKGROUND: Arthroscopic ankle arthrodesis (AAA) has become popular because of its higher rate of bone union, lower invasiveness, and shorter hospital stays compared to those of open arthrodesis. However, postoperative malalignment is often observed for severe varus deformity, which can cause nonunion, pain, and adjacent joint arthrosis. A compression staple can provide a persistent, strong compressive force on the bone surface. This study aimed to clarify the difference in alignment correction in AAA by comparing a compression staple and screws fixation with screws-only fixation pre- and postoperatively. METHODS: Seventy ankles in 67 patients undergoing AAA were retrospectively reviewed. AAA with three screws through the distal tibia was performed in 53 ankles, and 17 ankles underwent AAA with a compression staple and two screws. After the preparation of the joint surface arthroscopically, patients in the S group had three canulated cancellous screws inserted through the medial tibia. Patients in the CS group had a compression staple placed at the lateral aspect of the tibiotalar joint and two screws inserted through the medial side. Clinical scores and pre-and postoperative alignment on plain radiographs were compared between the two procedures. RESULTS: There were no significant differences in the pre-and postoperative Japanese Society for Surgery of the Foot scale. One ankle in the S group exhibited nonunion. There were no significant differences in talar tilt and tibiotalar angles between the groups. The tibial plafond angle in the CS group was significantly lower than that in the S group (p < 0.05). Postoperatively, talar tilt and tibiotalar angles on the coronal image, and the lateral tibiotalar angle in the CS group were significantly lower than those in the S group (p < 0.05). CONCLUSION: AAA with a compression staple and two-screw fixations could obtain more optimal alignments than AAA with screw-only fixation, even in cases with severe varus deformity.

Safe Insertion Angle of the Suture Button to Avoid Saphenous Structure in Syndesmosis Injury.

In placing the medial suture button for syndesmosis injury, the risk of great saphenous vein and saphenous nerve injury has been reported. This study aimed to determine the safe insertion angle of the guide pin to avoid saphenous structure injury during suture button fixation. The incidence of saphenous structure injury was investigated using 8 legs of cadavers. The greater saphenous vein was depicted on the skin using near-infrared light (VeinViewer® Flex) and the distance between the greater saphenous vein and the posterior edge of the tibia at levels of 10, 20, and 30 mm from the joint line of the tibiotalar joint was measured in the 60 legs of healthy participants. On computed tomography (CT) images, the angles between the greater saphenous vein and transmalleolar axis at levels of 10, 20, and 30 mm from the joint line of the tibiotalar joint were measured. The cadaveric study revealed that the percentages of contact with the saphenous nerve were 8.3% to 16.7%. Using near-infrared light, the vein and tibia distance was 32.9 ± 6.8 mm of 10 mm, 26.6 ± 6.4 mm of 20 mm, and 20.4 ± 6.4 mm of 30 mm. The angle between the vein and transmalleolar axis was 1.0° to 9.4°, and more proximal, the angle was smaller. The veins depicted by near-infrared light can be a landmark to identify great saphenous vein, and injury of the saphenous structure can be prevented using VeinViewer Flex or considering the insertion angle defined in this study when placing the suture button for syndesmosis injuries.Level of Evidence: Level IV.

Development of osteophytes and joint space narrowing is associated with cartilage degeneration of the osteochondral fragment in the osteochondral lesion of the talus.

BACKGROUND: During surgery for osteochondral lesions of the talus (OLT), preservation or excision of the osteochondral fragment is chosen based on the cartilage condition which influences the indication and clinical outcomes of surgical treatments. However, it is difficult to predict arthroscopic and histological findings of the cartilage on osteochondral fragments by radiographic evaluation. We focused on osteoarthritis (OA) changes on plain radiographs to predict the cartilage condition of the OLT. This study aimed to evaluate whether OA changes, including osteophyte and joint space narrowing, could predict arthroscopic and histological findings of the cartilage in OLT. METHODS: Seventy ankles with OLT were included in this study. Osteophytes and joint space narrowing were scored on plain radiographs. Lesion sizes were measured on computed tomography images. The cartilage surfaces of fragments were arthroscopically assessed using the International Cartilage Repair Society (ICRS) grade. Biopsy specimens from 32 ankles were histologically analyzed using the Mankin score. The relationships between OA scores, lesion size, ICRS grades, and Mankin score were analyzed. RESULTS: OA changes were frequently observed with increasing ICRS grades, especially in the medial tibiotalar joint. OA scores in patients with ICRS grade 1 were significantly lower than those in ICRS grades 2,3, and 4. The lesion sizes in patients with ICRS grade 3 and 4 were significantly smaller than those in patients with ICRS grade 1 and 2. Histological analysis showed increasing Mankin scores as the ICRS grade worsened. A mild correlation existed between the OA and Mankin scores (rs = 0.494). CONCLUSIONS: OA changes, such as osteophyte formation and joint space narrowing, are associated with arthroscopic findings of the articular surface and cartilage degeneration in osteochondral fragment in OLT. Articular cartilage conditions can be predicted by OA changes on plain radiographs, which is useful for choosing the appropriate treatment for patients with OLT. LEVEL OF EVIDENCE: Level Ⅳ, case series.

Lidocaine Tape Application for 3 Hours Prevents Vasovagal Syncope During Venipuncture: A Case Series.

Vasovagal syncope (VVS) or reflex is usually caused by physical and mental stress-related factors, like pain, anxiety, and fear, and it is one of the most frequent complications during dental treatment. Two patients, both with histories of dental phobia and of VVS during vaccination, venipuncture, and dental treatment with local anesthetics, were scheduled for dental treatment under intravenous (IV) sedation. However, both experienced episodes of VVS that occurred during venipuncture using a 24-gauge indwelling needle. We determined that pain was the main trigger of VVS for these patients and attempted to reduce venipuncture-associated pain using 60% lidocaine tape applied 3 hours before venipuncture at their next dental visits, respectively. Use of the lidocaine tape was successful and permitted comfortable placement of the IV catheter without any onset of VVS.

Evaluation of the flexion gap with a distal femoral trial component in posterior-stabilized total knee arthroplasty.

PURPOSE: A distal femoral trial component was manufactured, and flexion gap size and inclination were evaluated with or without the distal femoral trial component in total knee arthroplasty (TKA). This study aimed to evaluate the effect of the distal femoral trial component on flexion gap size and joint inclination in posterior-stabilized (PS)-TKA. MATERIALS AND METHODS: A total of 84 patients with medial osteoarthritis who underwent mobile-bearing PS-TKA using modified gap techniques were included in this retrospective study. The flexion gap size and inclination before and after setting the distal femoral trial component were evaluated and compared with the final gap size and inclination. RESULTS: The joint gap size and inclination were significantly lower in those with than in those without the distal femoral trial component (P = 0.005, P < 0.001). The final gap size and inclination were similar to the gap size and inclination with the distal trial component (P = 0.468, P = 0.158). CONCLUSIONS: The joint gap size and medial tension in PS-TKA were significantly reduced after setting the distal femoral trial component. The flexion gap measured using the distal femoral trial component was similar to that when the final trial component was set. To more accurately perform the gap technique TKA, the flexion gap should be measured using the distal femoral trial component.

Characteristic Bone Morphology Change of the Subtalar Joint in Severe Varus Ankle Osteoarthritis.

The subtalar joint has a possible compensatory mechanism for supramalleolar deformities; the failure of this mechanism causes the progression of ankle osteoarthritis. However, the reason for this failure has not been fully elucidated. This study aimed to evaluate the characteristics of the morphologic changes in the subtalar joint in varus ankle osteoarthritis using computed tomography. The study included 30 patients with severe osteoarthritis (modified Kellgren-Lawrence classification grade ≥ 3; mean age: 68.5 years) and 30 patients without- or with early osteoarthritis (grade 0-1; mean age: 43.0 years) as the control group. The location of cysts, osteophyte formation in the subtalar joint, and thickness of the subchondral bone plate were evaluated. In the osteoarthritis group, cyst formation was observed on the posterolateral side of the posterior facet of the calcaneus in 6 cases (20%) and of the talus in 7 cases (23.3%). Osteophyte formation was observed in the talus in 21 cases (70.0%) and in the calcaneus in 29 cases (96.6%). Osteophyte formation was observed on the posterior or lateral side of the posterior facet, and osteophyte contact between the talus and calcaneus was observed. The subchondral bone plate of the posterior medial side of the posterior facet of the talus was significantly thicker in the osteoarthritis group. The subtalar joint is less affected in severe varus ankle osteoarthritis containing a thickened subchondral bone plate in the posteromedial aspect of the posterior talar facet.

Accuracy of total knee arthroplasty using the modified gap technique based on the bone gap: an evaluation of the bone gap with a distal femoral trial component.

BACKGROUND: In total knee arthroplasty (TKA) using the modified gap technique, the soft-tissue balance is measured after osteotomy of the distal femur and proximal tibia (conventional bone gap). However, after osteotomy, the flexion gap size during 90° knee flexion may be larger than that observed after implantation. The tension of the lateral compartment during 90° flexion may also be reduced after osteotomy of the distal femur. We manufactured a distal femoral trial component to reproduce the condition after implantation and prior to posterior condyle osteotomy. This study aimed to evaluate the effect of the trial component on the flexion gap. METHODS: This prospective study included 21 consecutive patients aged 78 years with medial osteoarthritis who underwent cruciate-retaining TKA between February 2017 and March 2018. The postoperative flexion gap size and inclination during 90° flexion were compared between cases with and without the trial component. RESULTS: The mean joint gap size with the trial component (13.4 ± 0.80 mm) was significantly smaller than that without the trial component (14.7 ± 0.84 mm). The mean gap inclination angle with the trial component (3.7° ± 0.62°) was significantly smaller than that without the trial component (5.5° ± 0.78°). CONCLUSIONS: In the present study, the joint gap size and medial tension were significantly reduced after the trial component had been set. Accurate measurement of the soft-tissue balance is an important factor in the modified gap technique, and this method using a distal femoral trial component can offer better outcomes than those achieved with conventional methods.

A Case of Anaphylaxis in Which a Basophil Activation Test Was Used to Identify the Suspected Agent.

This is a case report of anaphylaxis in which the basophil activation test (BAT) was used to identify the etiological agent. Although skin tests are considered the most effective methods for identifying anaphylactic triggers, the test itself presents a risk of inducing anaphylaxis. The BAT is advantageous because of its inherent lack of risk, high sensitivity and specificity to identify the suspected anaphylactic agents, and diagnostic accuracy comparable to conventional skin testing. Therefore, in the future, the BAT is likely to become the preferred test for the detection of allergens over conventional skin tests.

Use of the Microcuff® During General Anesthesia for Patients With Scoliosis.

Scoliosis may often be associated with a variety of cardiovascular and respiratory conditions or diseases, and depending on the severity of the spinal deformity, it may also complicate anesthetic management because of the difficulty of neck extension and tracheal deformity. Therefore, patients with scoliosis may require careful perioperative anesthetic considerations. A 14-year-old girl was scheduled to undergo extractions and restorative treatment for dental caries under general anesthesia. Her medical history was significant for intellectual disability and autism as well as previously undiagnosed scoliosis. After fixation of a 6.0 Portex® endotracheal tube (ETT), percutaneous oxygen saturation (SpO2) decreased to 93%, peak airway pressures increased, and unilateral lung ventilation was noted. Inadvertent mainstem bronchial intubation was immediately suspected, prompting removal of the Portex ETT and reintubation with a shorter 6.0 Microcuff® ETT. The dental treatment was completed successfully without further incident. Assessment of the ETTs used intraoperatively led to the determination that the distance from the glottis to the carina was considerably shorter than normal for this patient. It was speculated that the Microcuff ETT may be optimal for anesthetic management of scoliosis patients because of its shorter lengths compared with other style ETTs, which may reduce the risk of bronchial intubation in such cases.

The effectiveness of educational methods for cricothyroid membrane identification by dental students: A prospective study using neck photographs and tracheotomy trainers.

The purpose of this study was to evaluate the accurate identification of the cricothyroid membrane (CTM) by fifth grade dental students, before undergoing the relevant anesthesiology practicum. Moreover, we aimed to determine the educational effectiveness of the cricothyrotomy practicum in anesthesiology. Before the lecture and without prior notification, 119 students were provided with a photograph of a man's neck and instructed to attach a blue sticker to the cricothyrotomy puncture site and to a palpable tracheotomy trainer, after applying sufficient palpation. After this, students attended a 60-min lecture on the emergency airway management method. Two and 16 days after the lecture and practicum, students were presented with a new neck photograph and the tracheotomy trainer and asked again to place stickers (red stickers: at 2 days; green stickers: at 16 days) on the cricothyrotomy penetration site. The data were analyzed with an image processing software, by superimposing the 119 stickers on the neck photographs and tracheotomy trainers, to visually examine the accuracy of CTM identification. The rate of correct sticker placement in the neck photographs was 41.2% before the lecture, 80.7% 2 days after the lecture, and 77.3% 16 days after the lecture (before vs. 2 and 16 days after, p value < 0.01). For the tracheotomy trainer, the rate was 36.1% before the lecture, 97.5% 2 days after the lecture, and 94.1% 16 days after the lecture (before vs. 2 and 16 days after, p value < 0.01). Furthermore, the proportion of students with mistakes above and below the CTM was higher than that of students with mistakes to the right or left. In conclusion, the rate of accurate CTM identification among dental students was low before they underwent the relevant practicum, but most students were able to identify the CTM accurately after the lecture and practicum in a small class.

Galvanic Tongue Stimulation Inhibits Five Basic Tastes Induced by Aqueous Electrolyte Solutions.

Galvanic tongue stimulation (GTS) modulates taste sensation. However, the effect of GTS is contingent on the electrode polarity in the proximity of the tongue. If an anodal electrode is attached in the proximity of the tongue, an electrical or metallic taste is elicited. On the other hand, if only cathodal electrode is attached in the proximity of the tongue, the salty taste, which is induced by electrolyte materials, is inhibited. The mechanism of this taste inhibition is not adequately understood. In this study, we aim to demonstrate that the inhibition is cause by ions, which elicit taste and which migrate from the taste sensors on the tongue by GTS. We verified the inhibitory effect of GTS on all five basic tastes induced by electrolyte materials. This technology is effective for virtual reality systems and interfaces to support dietary restrictions. Our findings demonstrate that cathodal-GTS inhibits all the five basic tastes. The results also support our hypothesis that the effects of cathodal-GTS are caused by migrating tasting ions in the mouth.

BDNF as a possible modulator of EEG oscillatory response at the parietal cortex during visuo-tactile integration processes using a rubber hand.

Multisensory integration of visuo-tactile information presented on the body or a dummy body has a strong impact on body image. Previous researches show that alteration of body image induced by visuo-tactile integration is closely related to the activation of the parietal cortex, a sensory association area. The expression of brain-derived neurotrophic factor (BDNF) in the parietal area of macaque monkeys is thought to modulate the activation of the parietal cortex and alter the extension of body image during tool-use learning. However, the relationship between parietal cortex activation related to body image alterations and BDNF levels in humans remains unclear. We investigated the relationship between human serum BDNF levels and electroencephalography responses during a visuo-tactile integration task involving a rubber hand. We found cortical oscillatory components in the high frequency (gamma) band in the left parietal cortex. Moreover, the power values of these oscillations were positively correlated (p<0.05) with serum BDNF levels. Our results suggest that serum BDNF could play a role in modulating the cortical activity in response to visuo-tactile integration processes related to body image alteration in humans.

IV ATP potentiates midazolam sedation as assessed by bispectral index.

In this study, by measuring bispectral index (BIS), we tested the hypothesis that intravenous adenosine 5'-triphosphate (ATP) infusion would deepen the level of midazolam-induced sedation. Ten healthy volunteers underwent 2 experiments with at least 2 weeks' interval: immediately after intravenous bolus administration of midazolam (0.04 mg/kg), they received continuous infusion of either ATP infusion (100 µg/kg/min) or placebo (saline) for 40 minutes in a double-blind, randomized, crossover manner. Changes in BIS values and responsiveness to verbal command as well as cardiorespiratory variables were observed throughout the study periods. Administration of midazolam alone reduced BIS value from control: 97 ± 1 to 68 ± 18 at 25 minutes, which was accompanied by significant cardiopulmonary depressant effects, while maintaining responsiveness to verbal command (consciousness) throughout the study period. Coadministration of ATP with midazolam further reduced BIS value to 51 ± 13, associated with complete loss of consciousness without adverse effect on the cardiorespiratory systems. We conclude that the addition of ATP infusion to midazolam significantly enhances midazolam sedation without disturbing cardiorespiratory functions.

Aminophylline reversal of prolonged postoperative sedation induced by propofol.

Propofol is frequently used for intravenous sedation or anesthesia in ambulatory and office-based anesthesia. Although awakening is usually rapid, there are instances of delayed recovery from propofol anesthesia. It has been reported that aminophylline antagonizes the sedative effects of several anesthetic and analgesic drugs. The case reports presented here demonstrate that intravenous aminophylline effectively reversed prolonged propofol-induced sedation/anesthesia in the postoperative period. There were no side effects or delayed re-sedation after the administration of aminophylline. Our study suggests that aminophylline could be a clinically useful propofol antagonist.

The characteristics of intravenous adenosine-induced antinociception in a rabbit model of acute nociceptive pain: a comparative study with remifentanil.

BACKGROUND: Adenosine and remifentanil are potent IV analgesics with ultrashort half-lives. The antinociceptive effect of IV adenosine has not been clearly characterized. We compared the antinociceptive effects of adenosine and remifentanil in rabbits. METHODS: Sixteen rabbits, placed on a sling allowing reasonably free movement, received IV adenosine (400 microg x kg(-1) x min(-1)) or remifentanil (0.4 microg x kg(-1) x min(-1)) over 240 min. RESULTS: Both drugs produced profound antinociception, as assessed by the number of animals unresponsive to clamping the forepaw and the electrical stimulation threshold of escape movement. With remifentanil, the antinociceptive effect increased rapidly, reaching its peak at 60 min, and then began to decline despite continued infusion. After stopping the infusion, it decreased rapidly and disappeared within 30 min. The vasodilating effect of IV adenosine was immediate in onset and ultrashort in duration. The antinociceptive effect of adenosine increased slowly but progressively during the infusion, reaching its peak only when the infusion ended. Then it decreased slowly over the following 360 min after terminating the infusion. CONCLUSION: Remifentanil had a rapid onset and short duration of action, and probably showed signs of tolerance development, whereas the antinocieptive effect of adenosine was slow in onset and long-lasting, despite its ultrashort plasma half-life and the immediate on-off profiles of its vasodilating effect.